HaXe compiles to PHP
lists.motion-twin.com
haXe is a ECMAScript-like language and compiler that targets multiple runtime platforms: Flash, Javascript, NekoVM, and now PHP (in alpha form).
As a user, I'm biased, but this compiler really extends the meaning of "Write once, run anywhere." haXe code running on Java, Python, Ruby, etc. is not out of the question, if anyone steps up to add those targets.